1. Field of the Invention
This invention relates generally to a cutter-separator for food and agricultural products. More particularly, but not by way of limitation, the present invention relates to a device in which material is supplied under pressure to the inner bore of an oscillating spring wherein desirable product is extruded through the space between the coils when the spring is in a stretched state, thereby separating desirable product from undesirable matter, and size reduction of the desirable product thus separated, is performed by the action of the coils when the spring is in a compressed state.
2. Background
Traditionally, cutting, grinding and size reduction processes used for food and agricultural products involve the use of devices with rotating blades, plates, cones, or rollers with fixed orifice plates or screens and a feed mechanism. Common names for these types of machines are hammer mill, grinder, crusher, cutter, attrition mill, and comminuter. Many of these devices provide no mechanism for separating foreign matter such as bone, plastic, metal, or glass from the product. In these cases, contaminants are processed along with the product making them increasingly difficult to detect and remove.
Equipment of this type often has dangerous moving parts and hazardous, sharp blades. Many of the blades used in such equipment are sharp enough to cut, even when motionless, posing hazards to sanitation and maintenance crews. In addition, some grinders utilize high-speed, rotating shafts, close tolerance blades, and stators. These parts are expensive to replace and costly to maintain. An ideal size reducer would have the following operating characteristics: (1) it would produce uniform product size; (2) its use would result in minimal temperature rise in the product; (3) it would require minimal power to operate; and (4) it would provide trouble free-operation.
It is thus an object of the present invention to provide a cutter-separator which will reliably separate foreign material from desirable product prior to the size reduction process.
It is a further object of the present invention to provide a cutter-separator which avoids the use of hazardous parts and thus, poses a reduced physical threat to the operator or maintenance personnel.
It is another object of the present invention to provide a cutter-separator which, in operation, will produce product of uniform size.
It is yet another object of the present invention to provide a cutter-separator which, in operation, will produce minimal temperature rise in the product.
These and other objects and advantages are achieved in a cutter-separator which uses an oscillating spring to first separate contaminants from the product and then to reduce the product to a uniform size.
In the inventive cutter-separator, product is fluidized under pressure, forced through the bore of a spring and thence through the gaps between the coils of the spring while in its extended condition. When the spring returns to its compressed, or relaxed, condition the product which has been forced through the coils is reduced in size (i.e., cut, partially cut, or mashed, as desired) by the spring. Contaminants which are too large to pass between the coils are ultimately carried to the end of the spring, downstream from the product flow, where they are discharged.
In one embodiment of the inventive device, pressure is obtained by an auger which rotates inside the bore of an oscillating spring. As product is forced into the spring by the auger, pressure causes the product to fluidize and pass between the coils of the spring while separated. As the spring returns to its compressed state, the product is cut to size. Separation is accomplished because the pressure is insufficient to fluidize dense particles, i.e., bone chips, glass, metal, and the like. These dense particles are carried along the axis of the auger and discharged through an opening in a backpressure plate. Contaminants will not pass between the spring gaps as long as they are larger than the gaps. This results in a product stream, exiting through the spring coils, which is separate from the contaminant stream, exiting at the backpressure plate.
A better understanding of the present invention, its several aspects, and its objects and advantages will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the attached drawings, wherein there is shown and described the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated for carrying out the invention.